Coil retaining and ventilating means.



A. ELD & E. FORNANDER.

COIL NG AND VENTILATING MEANS.

PPL TION FILED FEB.5.I9 14.

Patented May 21, 1918.

UNITED STATES PATENT OFFICE.

ALLAN BERTRAM FIELD, OF WESTCLIFF-ON-SEA, ENGLAND, AND ERIC FORNANDER, OF WILKINSBURG, PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, CORPORATION OF PENNSYLVANIA.

COIL RETAINING AND VENTILATING MEANS.

Specification of Letters Patent. Patented May 21, 1918. Application filed February 5, 1914. Serial No. 816,857.

To all whom it may concern:

Be it known that we, ALLAN B. FIELD, a subject of the King of England, and a residentrof Westcliff-on-Sea, Essex, En land, and ERIC FORNANDER, a citizen of the nited States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Coil Retaining and Ventilating Means, of which the following is a specification.

Our invention relates to dynamo-electric machines, and it has special reference to coilretaining and ventilating rings particularly adapted for employment in the rotors of turbo-generators and similar machines.

The object of. our invention, in its broad aspect, is to provide an improved system of ventilation in apparatus of the above-indicated character, whereby, not only will the overhanging end-portions of the coils be suitably held in position and cooled by currents of air or other medium produced by rotation of the parts, butalsothe medium will discharge from the coil end-portions into the machine air-gap in such a manner that afurther current of cooling fluid. from outside is induced through the air gap, the operating losses and deterioration of the parts from heating being reduced in this manner.

In the prior art, the necemity has been recognized for ventilation'of the overhanging end-portions of coils in the rotors of turbo-generators in particular, such rotors, usually for mechanical reasons, employing a coil-retaining ring that more or less completelyincloses the end portions and, consequently, prevents a free circulation of air .therethroughh In an "attempt to meet the conditions, various expedients, 'suchas pro- .viding radially-disposed openings in. the ring or in the core where thexring fits on, have been adopted. Howeveig'in the operation of a machine equippedin' the manner just described, it has been found that the radial discharge of the'ventilating air has interfered considerably 'with the passage through the air gap of cooling air, which is so desirableifrom an operating. standpoint.

suitably,

According to our present invention, we provide a coil-retaining ring provided with a relatively thin axially extending flange for engaging the core adjacent to the machine air gap, and having a plurality of inclined ventilating passages extending through the flange to the air gap. Air is forced in through an apertured plate associated with the machine shaft and radially supporting the outer edge of the ring. The air, after ventilating the end-portions of the coils, is thus discharged through the inclined openings into the air gap and in the general axial direction thereof, thereby serving to induce an increased flow of air through the g P- In the accompanying drawing, Figure 1 is a view, in longitudinal section, of a portion of a dynamo-electric machine embodying our invention,'Fig. 2 is a view in front elevation of a portion of the coil-retaining ring shown in Fig. 1; and Fig, 3 is an enlarged sectional view on the line III-11]: of Fig. 2.

Referring to the drawing, the portion of a dynamo-electric machine, here shown as a turbo-generator, comprises a stator 1 a rotor Q'that is separated therefrom by an air-gap 2 and is provided with coils of a familiar type having overhanging end-portions 3, a shaft 4, and our coil-supporting and ventilating device 5 associated with the end-portions 3 and the shaft 4. It will be understood that, for the most part, the details of construction of the dynamo-electric machine employing our invention are more or less optional and are not relevant to the invention; consequently, only so much of the machine as is requisite to a clear understanding of the arrangement and operation of the device 5 will be described.

The core 6 of the rotor 2 has an outermost portion 7 that is relatively narrow and of smaller diameter than the core proper. The portion referred to preferably constitutes an end-plate of familiar construction. A'section 8 contiguous to the portion 7 is preferably inclined outwardly to the core surface for a purpose hereinafter described.

I The coil-supporting and ventilating device plate 10.

The ring 9 tightly incloses the coil endportions 3, being insulated therefrom by baked mica sheets or other suitable material,

and its axially outer edge is'suitably recessed to receive the outer edge of the plate 10. At its inner end, the ring is provided w th a relatively thin axially extending flange 12 that is adapted to engage the outermost por ti'on or plate 7 of the core. Through a portion of the flange and through theadjacent edge of the ring extend a plurality of spaced ventilating passages 13 (best shown, in, Fig. 2) that are thus disposed adjacent and approximately parallel to the inclined section 8.

The plate 10 fits around the shaft 1 to preferably abut against an annular shoulder 1 1 thereof, and engages the outer edge of the ring 9, as hereinbefore described. A plurality of axial apertures 15 areprovided in the plate 10 for ventilating, purposes.

The positioning device 11 is here shown as a nut disposed upon a threaded portion of the shaft 1 and is adapted to rigidly hold the plate 10 against the shoulder 14 and the retaining-ring 9, thereby satisfactorily positioning the entire coil-retaining and ventilating device. It will, however, be understood'that other suitable positioning devices may be employed if desired.

In Fig. 2 are shown a pair of diametrically oppositely disposed slots or keyways 16 in the flange 12. Similarly spaced slots 17 are provided in the inclined section 8 and in order to prevent circumferential movement of the ring 9 keys or wedges 18 are suitably positioned in the slots, as best shown in Fig. 3.

It will be noted that the contact surface between the ring 9 and the'core 6 is of relatively small area, thus keeping the stray power losses in the ring, by reason of leakage of magnetic flux from the rotor, at a relatively small value.

The operation of the dynamo-electric machine, in so far as our present invention is concerned, will be apparent from the foregoing description. Air or other suitable ventilating medium is forced into the inclosing endbell of the stator from a suitable external source and enters the apertures 15 of the plate 10 to cool the coil end-portions 3. The air then passes through the inclined passages 13 into the machine air gap 2? and in a longitudinal direction as indicated by the solid arrows, this inducing a further current of air from outside through the air-gap, as indicated by the dotted arrows. The operating advantages of such an arrangement have already been mentioned.

We do not wish tobe restricted to'the particular structural details and arrangement of parts herein set forth, but desire that only such limitations shall be. imposed as are indicated in the appended claims.

We claim as our invention:

i a yn m -e e tr machine, the cQmbination with relatively rotatablemagnetizable members, one of which isprovided with coils having overhanging'end-portions, of a peripheral memberfor supporting said endportions and rovided with ventilating passages arranged to discharge into, the air gap between said relatively rotatable members and longitudinally, thereof.

2. In a dynamo-electric machine, the combination with a stator'core and a magnetizable rotor core provided with coils having overhanging end-portionspof a peripheral member disposed adjacent? to the airgap'between the stator and rotorcores for supporting said end-portions and provided with .ventilating openings arranged to dischar e outwardly' into. the air gap and longitudinally thereof to induce additional ventilatingcurrents through said, air gap.

3. In a dynamo-electric machine, the com.-

bination with relatively rotatable magnetizable members, one of which is providedwith coils having overhanging end-portions, of a peripheral member for supporting said end-portions and. provided with ventilating passages arranged to discharge longitudinally into the air gap between saidrelatively rotatable members to induce-additional ventilating currents through said air gap.

4. In a dynamo-electric machine, the combination with a magnetizable core provided with coils having overhanging end-portions, of a retaining ring for saidend-portions, the longitudinallyinner and relatively thinrim of said ring. being a dcpted to enga e the edge of said core andhaving a pluraIity of spacedventilating passages inclined from its inner periphery to themachine air gap, an apertured radial plate mechanically. associated with the machine shaft for supportingthe outer end of saidring, and means for rigidly positioningsaid plate.

5. Ina dynamo-electric machine, the combination with: amagnetizable core provided with coilshaving' overhanging endeportions, and a shaft therefor having a shoulder located adjacent to one end of the core, said end having a relatively narrow outermost portion of smallerdiameter andya contiguous section inclined to-meet-the core-surface, of a retaining ring for said-end-portion's provided with: a relatively thin flange adapted to engage said'outermost .portion of the core, said ring having in the flange -and-in the adjacent edgea plurality of-fspaced ventilating passages disposed adjacent and "approximately parallel to said inclined section of the core, an aperturedyradial plate engaging. said shoulder on the shaft-"for supsubscribed our names this 15th day of Jannary, 1914.

ALLAN BERTRAM FIELD. ERIC FORNANDER. Witnesses as to Allan Bertram Field:

ARTHUR HENRY HOPPER, W. I. SKERTEN. \Vitnesses as to Eric Fornander:

EMIL MA'i'rMAN,

B. B. Hmns.

Copies of this patent may be obtained for five cents each by addressing the Commissioner of Patents,

Washington, D. G. 

